Syringe assembly for withdrawing two separate portions of fluid following a single engagement with fluid port

Abstract

In one or more embodiments, there is a dual syringe for the collection of fluid samples which enables taking two distinct samples, and a method of use thereof. Preferably the dual syringe is for single use. Generally, the dual syringe has three components: an outer barrel; an inner barrel that fits inside the outer barrel, locks to the outer barrel and has a rubber fitting on its tip so it can function as a plunger for the outer barrel; and a plunger for the inner barrel. There is a one-way valve in a nozzle opening or passage of the inner syringe enabling inward flow only. In a method of use, an initial portion of sample fluid, e.g., from a sampling port of a bioreactor vessel, is drawn into the inner barrel of the device by pulling on the plunger. The one-way valve prevents backflow of that initial portion of sample fluid thereby protecting the ideally aseptic chamber of the outer barrel. A subsequent sample can then be collected in the outer barrel without the two samples by overcoming or otherwise unlocking the inner barrel from the outer barrel, and pulling on the inner barrel. The sample in the outer barrel is distinct from the sample in the inner barrel. Each barrel can establish direct communication with the device tip, allowing the user to draw two distinct samples that do not interact with each other.

What is claimed is: 
     
         1 . A dual syringe, the dual syringe comprising:
 an inner barrel having a longitudinal axis;   a plunger disposed in the inner barrel and movable with respect to the inner barrel along the longitudinal axis; and   an outer barrel having the inner barrel disposed therein and the inner barrel being movable with respect to the outer barrel along the longitudinal axis and having a forward end with a nozzle communicating an exterior of the outer barrel with an interior of the outer barrel,   wherein the inner barrel has a nose portion with a fluid passage defined therein in communication with the nozzle when the inner barrel is fully inserted in the outer barrel, and wherein the inner barrel has a one-way valve disposed in the fluid passage allowing fluid to pass from outside the inner barrel to an inside of the inner barrel.   
     
     
         2 . The dual syringe of  claim 1 , wherein the plunger is movable between a fully inserted position where a tip of the plunger blocks the fluid passage from communication with the inside of the inner barrel, and wherein when the plunger is at least partly withdrawn from the fully inserted position, an inside chamber is formed inside the inner barrel for allowing fluid to pass from outside the inner barrel to an inside of the inner barrel. 
     
     
         3 . The dual syringe of  claim 1 , wherein the inner barrel is movable between a fully inserted position in the outer barrel where a forward portion of the inner barrel blocks fluid communication of the nozzle with the interior of the outer barrel and an at least partly withdrawn position where the nozzle is open to communicate with the interior of the outer barrel for allowing fluid to pass from outside the outer barrel to the interior of the outer barrel. 
     
     
         4 . The dual syringe of  claim 1 , further comprising means for retaining the inner barrel in the fully inserted position when the plunger is being withdrawn from the inner barrel. 
     
     
         5 . The dual syringe of  claim 4 , wherein the means for retaining comprises an interference fit of the inner barrel and the outer barrel. 
     
     
         6 . The dual syringe of  claim 4 , wherein, at an end of the outer barrel opposite the forward end, the outer barrel has a flange end and the inner barrel has a flange portion, wherein the means for retaining comprises an interference fit between the flange end of the outer barrel and the flange portion of the inner barrel. 
     
     
         7 . The dual syringe of  claim 5 , wherein the flange end and the flange portion each extend transverse to the longitudinal axis and the interference fit is provided by the flange portion having gripping members therein that extend to and grip the flange end. 
     
     
         8 . The dual syringe of  claim 1 , wherein, at an end of the outer barrel opposite the forward end, the outer barrel has a flange end and the inner barrel has a flange portion, and the flange end and the flange portion each extend transverse to the longitudinal axis and have an interference fit provided by the flange portion having gripping members therein that extend to and grip the flange end. 
     
     
         9 . The dual syringe of  claim 4 , wherein the plunger has an elastomeric seal at a forward end thereof for sealing the fluid passage from communication with the inside of the inner barrel when the plunger is fully inserted in the inner barrel, and the rubber seal having a circumferential surface which is friction fit against an inner radial surface of the inner barrel, and the inner barrel has an elastomeric fitting at its forward end for forming a seal around the nozzle so as to seal the nozzle from communication with the interior of the outer barrel, and the elastomeric fitting has a circumferential surface which is friction fit against an inner surface of the outer barrel, wherein a force of static friction necessary for relative motion of the inner barrel and the outer barrel is greater than a force of static friction necessary for relative motion of the plunger and the inner barrel. 
     
     
         10 . The dual syringe of  claim 1 , wherein the inner barrel has a mounting member extending toward the fluid passage of the outer barrel and extending from a forward end of the inner barrel, and has an elastomeric fitting mounted around the mounting member. 
     
     
         11 . The dual syringe of  claim 10 , wherein the elastomeric fitting and the one-way valve are formed in one piece. 
     
     
         12 . The dual syringe of  claim 1 , wherein the one-way valve is a duckbill valve. 
     
     
         13 . The dual syringe of  claim 1 , wherein the inner barrel has externally extending ridges for stabilizing the inner barrel within the outer barrel. 
     
     
         14 . The dual syringe of  claim 1 , further comprising a barrier member which is disposed between the outer barrel and the inner barrel to keep contaminants from entering a space between the inner barrel and the outer barrel. 
     
     
         15 . A dual syringe, the dual syringe comprising:
 an inner barrel having a longitudinal axis;   a plunger disposed in the inner barrel and movable with respect to the inner barrel along the longitudinal axis; and   an outer barrel having the inner barrel disposed therein and movable with respect to the outer barrel along the longitudinal axis and having a forward end with a nozzle communicating an exterior of the outer barrel with an interior of the outer barrel,   wherein the inner barrel has a nose portion with a fluid passage defined therein in communication with the nozzle when the inner barrel is fully inserted in the outer barrel,   wherein the plunger is movable between a fully inserted position where a tip of the plunger blocks the fluid passage from communication with the inside of the inner barrel, and wherein when the plunger is at least partly withdrawn from the fully inserted position an inside chamber is formed inside the inner barrel, the fluid passage for allowing fluid to pass from outside the inner barrel to an inside of the inner barrel, and   wherein the inner barrel is movable between a fully inserted position in the outer barrel where a forward portion of the inner barrel blocks fluid communication of the nozzle with the interior of the outer barrel and an at least partly withdrawn position where the nozzle is open to communicate with the interior of the outer barrel for allowing fluid to pass from outside the outer barrel to the interior of the outer barrel.   
     
     
         16 . The dual syringe of  claim 15 , wherein the plunger has an elastomeric seal at a forward end thereof for sealing the fluid passage from communication with the inside of the inner barrel when the plunger is fully inserted in the inner barrel, and the rubber seal having a circumferential surface which is friction fit against an inner radial surface of the inner barrel, and the inner barrel has an elastomeric fitting at its forward end for forming a seal around the nozzle so as to seal the nozzle from communication with the interior of the outer barrel, and the elastomeric fitting has a circumferential surface which is friction fit against an inner surface of the outer barrel. 
     
     
         17 . The dual syringe of  claim 16 , wherein the inner barrel has a mounting member extending toward the fluid passage of the outer barrel and extending from a forward end of the inner barrel, and has an elastomeric fitting mounted around the mounting member, and the plunger has an elastomer seal disposed at the forward end thereof. 
     
     
         18 . The dual syringe of  claim 15 , wherein the outer barrel is for a standard 20 ml syringe and the plunger is for a standard 10 ml syringe. 
     
     
         19 . The dual syringe of  claim 15 , further comprising a barrier member which is disposed between the outer barrel and the inner barrel to keep contaminants from entering a space between the inner barrel and the outer barrel. 
     
     
         20 . A dual syringe, the dual syringe comprising:
 an inner barrel having a longitudinal axis;   a plunger disposed in the inner barrel and movable with respect to the inner barrel along the longitudinal axis; and   an outer barrel having the inner barrel disposed therein and the inner barrel being movable with respect to the outer barrel along the longitudinal axis and having a forward end with a nozzle communicating an exterior of the outer barrel with an interior of the outer barrel,   wherein the inner barrel has a nose portion with a fluid passage defined therein in communication with the nozzle when the inner barrel is fully inserted in the outer barrel and the inner barrel has means for allowing fluid flow from the nozzle into the inner barrel in a first direction via the passageway and for preventing fluid flow from the inner barrel through the passageway in a second direction opposite to the first direction, and wherein the interior of the outer barrel is in communication with the nozzle when the inner barrel is at least partly withdrawn from the outer barrel, and wherein a tip of the outer barrel has a fitting disposed thereon in fluid communication with the nozzle and for fluid tight mating with another fitting.   
     
     
         21 . A method of use of a dual syringe for obtaining a desired sample fluid, the dual syringe comprising:
 an inner barrel having a longitudinal axis;   a plunger disposed in the inner barrel and movable with respect to the inner barrel along the longitudinal axis; and   an outer barrel having the inner barrel disposed therein and movable with respect to the outer barrel along the longitudinal axis and having a forward end with a nozzle communicating an exterior of the outer barrel with an interior of the outer barrel,   wherein the inner barrel has a nose portion with a fluid passage defined therein in communication with the nozzle when the inner barrel is fully inserted in the outer barrel, and   wherein the inner barrel has a one-way valve disposed in the fluid passage allowing fluid to pass from outside the inner barrel to an inside of the inner barrel, and   wherein the method comprises the steps of:   a. connecting the forward end at the nozzle with a sampling port for a fluid to be sampled to make a fluid tight connection between the nozzle and the sampling port;   b. at least partially withdrawing the plunger from the inner barrel until a first portion of the fluid to be sampled is drawn into and disposed in the inside of the inner barrel; and   c. at least partially withdrawing the inner barrel from the outer barrel until a second portion of the fluid to be sampled is drawn into and disposed in the interior of the outer barrel.   
     
     
         22 . The method of  claim 21 , wherein the steps b and c are performed while maintaining the fluid tight connection with the sample port as formed in step a. 
     
     
         23 . The method of  claim 21 , wherein the second portion of the fluid is expelled as needed for use as the desired sample fluid by pressing the inner barrel or plunger towards the fully inserted position while the first portion of the fluid is maintained in the inside of the inner barrel by the one-way valve. 
     
     
         24 . The method of  claim 21 , wherein the fluid comprises one of a biologic fluid which is a cell culture or body fluid.